1. Field of the Invention
This invention relates to digital transmission systems and, more particularly, to the transmission of a single high-speed serial data stream between two points using a plurality of lower speed telecommunications channels.
2. Description of the Prior Art
It is well known in the prior art how to multiplex a plurality of lower speed data signals so as to produce a signal that can be transmitted over a standard wideband digital telecommunications channel. Indeed telecommunications companies have been accepting data signals at standard rates of 2.4 kb/s, 4.8 kb/s, 9.6 kb/s, and 56 kb/s and performing the multiplexing at telephone central offices. The use of standardized data signal rates enables use of the switched telecommunications network to interconnect various data terminals.
A signal which differs from one of the standard rates mentioned earlier requires processing to conform to the acceptable rates. This requirement places a substantial burden on the subscriber in several ways, one of which is limitation in the design of his terminal equipment.
Yet another problem arises when a customer wishes to transmit a data signal which has a repetition rate which is higher than the telecommunication company's carrier channel or that which a telephone switching system can handle. The only solution available in the prior art was to use wideband non-switched private line facilities between the two transmission terminals. This solution, however, required the installation of expensive transmission facilities dedicated to a single use.